Process of drawing glass cylinders



W. WESTBURY. PROCESS OF DRAWING GLASS CYLINDERS.

APPLICATION FILED OCT-15,1911- 1,344, 325'. Y Patented June 22, 1920.

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- PROCESS OF DRAWING GLASS CYLINDERS.

APPLICATION FILED OCT. 1.5. I917- 1,344:,325. Patented June 22, 1920.

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attorncq UNITED STATES PATENT OFFICE.

WILLIAM WESTBURY, 0F OKMULGEE, OKLAHOMA.

PROCESS OF DRAWING GLASS CYLINDERS.

To all whom it may concern:

Be it known that I, WILLIAM VVns'rBURY, a citizen of the United States, residing at Okmulgee, in the county of Okmulgee and State of Oklahoma, have invented new and useful Improvements in Processes of Drawing Glass Cylinders, of which the following is a specification.

This invention relates to a process of drawing glass cylinders for use in the production of window glass, etc., whereby greater rapidity of action, economy of manufacture, uniformity of operation in the proportion of perfect draws made and other substantial advantages are gained over the methods customarily employed.

Heretofore, two specifically different methods of drawing glass cylinders have been generally used. One of these, which may be termed the direct-draw or openbottom-pot method, involves the direct drawing of the cylinder from a body of molten glass within a glass melting furnace through what is known as a drawing opening in the top stone of the furnace body or a so-called doghouse communicating with the furnace body. The objection to this method is twofold. In the first place,,the body of glass disposed directly beneath the drawing opening is more or less exposed to the chilling effects of the atmosphere, resulting in its surface reduction of temperature and-the formation of crusts mixing with the pure liquefied glass, interfering with the drawing action and adding to the cost. of fuel required to keep the body of glass at the required temperature. In the second place, as the portion of glass from which the cylinder is drawn is exposed to the heat of the mass or body of glass within the furnace, the glass cools very slowly to the degree required to form the cap and initial portion of the cylinder, thus reducing the speed of the drawing action to a considerable extent. In an attempt to overcome these objections, various devices have been employed to shield the body of glass from atmospheric chilling, and floating rings or pots more or less open at the bottom have been used for the purpose of segregating a charge of pure hot glass from the body of surface-chilled glass within the portion of the furnace beneath the drawing opening. The use of such a pot or ring is of advantage from the standpoint of segregating a portion of the glass from the impurities and denatured Specification of Letters Patent. Patented June 22 192() Application filed October 15, 1917.

Serial No. 196,674.

' glass upon the body of glass within the i into the body of glass Without rehandling,

but still leaves the operation open to the objection of the segregated portion of glass being exposed to the heat of the main body of glass and cooling too slowly for a quick draw. Modifications of this method have been suggested, having for their object the shielding of the segregated charge of glass from the intense heat of the main body of glass, but none of these has been efficient in attaining the desired end.

In the other method referred to and which may be termed the indirect-draw or closedpot method, the glass is melted in one furnace and ladled into a closed-bottom pot supported and heated by a separate furnace. This requires the use of two separate plants I with additional labor and handling of parts and the rehandling and return of the aftermath by manual labor or mechanical means to the melting furnace. This indirect method has one advantage over the direct method first named, in that the glass is exposed directly to open-air cooling and is insulated largely by the bottom of the pot from the heat below, which is just sufiicient to keep it properly liquefied, whereby the glass is permitted to rapidly cool below its initial temperature and to set quickly for a rapid cap formation and drawing action. One of these methods is, therefore, advantageous in having its working parts combined in a single apparatus, but open to the objection of slowness in starting the draw, while the other method is, on the other hand, objectionable in the use of separate furnaces, although allowing greater speed and a material saving of time in starting the draw.

The object of my invention is to provide a process whereby all the advantages of these methods may be gained and the disadvantages thereof obviated, and whereby a cylinder may be formed from a charge of glass taken from the melting furnace, drawn from a pot which closes or seals the drawing opening and in which the charge of glass is exposed to atmospheric cooling while protected from the heat of the furnace, and

the residue or aftermath returned to the enabling the operation of drawing glass cylinders to be carried on with less labor, time and expense.

In th accompanying drawing showing one term of apparatus which may be employed for carrying my process into practical effect:

Figure 1 is a vertical section through a part of a glass melting furnace, showing a drawing station and illustrating the'pot in drawing position;

Fig. 2 is a view showing the pot in drawing position, and also showing two positions to whirh the pot may be adjusted for a reversing action;

Fig. 3 is a diagram oi a furnace;

Fig. lis a view in front elevation of the pot and the means for raising and lowering the same;

.l i is a sectional view through double reversible pot which may be employed; and

Fig. 6 is a similar view of a single reversible pot which may be employed.

in carrying my invention into prac"" effect. l provide a suitable type ct appa including a: glass melting furnace 1 containing a body of liquefied glass 2 from which charges of glass are supplied to the drawing pot 3 or 3 tor successive drawing ac tions. the interior oi the furnace being heated in any preferred. manner. The furnace is provided with a top stone 4 formed with one or more drawing openingsf), a single di -owing opening being shown in the present instance as suflicient to illustrate the invention. Openings 5 (one or more) are provided in the front wall oi the furnace for the insertion ot a ladle, tor the extraction of charges of glass to be supplied to the drawing pot. These openings are locat d a point or points more or less remot. .1 the drawing station or stations. here two or more drawing stations are employed, these openings, for convenience, may be arranged between the drawing stations. In such event, the ladlemay be mounted on a arriage adapted to run upon a track, whereby the ladle may be conveniently moved between the extracting openings and drawing stations. The pot 1s shown in the term oi a. double reversible pot comprising superposed pot sections 6 and 7 having closed bottoms h arranged in abutting contact and glass receivin cavities or chan'ihers-f) facing in opposite directions, the pot being reversible to alternately bring the chambers 9 into charge eceiving and draining positions. The pot maybe made, usual, of clay or other suitable refractory material.

The pot sections 6 and 7 are detachably connected by hollow clamping heads 10 having water chambers 11 for the circulation of water therethrough. The clamping heads are also provided with hollow spindles or trunnions 12 communicating with the water chambers and journaled in coupling l. oar lugs 13 upon the lower ends oi pot supports. Each of these supports comprises a pair oi upright concentric pipes or tubes M and 15, the outer pipes 14: forming discharge or waste pipes for the flow of the hot water from the chambers 11, while the pipes 15 serve as conductors for supplying cool nter from a suitable source to said chambers. A. circulation of water is thus provided for absorbing the heat from the pot to prolong the period oi lite thereof and to ca: y oil the heat from the clamps to adapt them to sustain the high tem erature to which they are subjected. The pot 3 is supported in the same manner as the pot 3 and consists of a single closed bottom pot, namely, a pot l'iaving a single chamber for the reception of the glass. ln each form of not, the pot is thus reversibly mounted in the conducting bearings by the spindles or trimnions 12 ot' the heads 10, which spindles or truuoions 12 are rotatably mounted in the comlucling bearings 13.

The pipes 14 and 15 are connected at their upper ends with couplings 16 with which are connected flexible pipes or tubes 17 and it} for the respective discharge of the hot water from the pipes 14 to any desired point and the supply 0t cold water from any suitable source to the pipes 15. The pipes 14; are slidably mounted in suitable guides 1.) upon a frame 20 depending from an oven head carriage 21, and this carriage is pro vided with guide sleeves 22 in which are siidably mounted rods 23 connected with the couplings 16. The rods 23. terminate at their upper ends in rack bars 24 engaging gears 25 on a shaft 26 forming part of a hoisting mechanism 27, whereby the pot and its supports may be raised and lowered with relation to the plane or the drawing opening.

Also mounted upon the frame 20 are guides 28 on which is slidably mounted the draw-carriage 29 supporting the drawing tool comprising the bait 30 and blow pipe or air supply pipe 31, which pipe may connect, in practice, in any suitable manner with a source of air supply to conduct air to the interior of the cylinder as it is being drawn. The carriage 29 is connected, in p active, by a cable 32 with any suitable type of hoist ing gear (not shown) mou'nted upon the carriage 21 or within a pent house (not shown). The carriage 21 is mounted upon a. track 33 which may extend between the furnace and the )ent house, thus allowing the drawing mec anism in its entirety to he raised clear of the drawing station and transported to the pent house for convenience in repairing or replacing the pot or other damaged or worn out parts, or to move the drawn cylinder clear of the furnace for the take-down action.

Arranged within the furnace is a drain ring 34- composed of any suitable refractory material adapted to float upon the surface of the glass, and which may be pushed back and forth between the body of the furnace and the drawing station by means of a suitable tool.

In carrying the invention into practical effectfor the drawing of a cylinder, the pot 3 is positioned to fit within the drawing opening and so as to project slightly above the top stone, and a charge of glass is then extracted from the furnace through one of the openings 5 and this charge of glass supplied to the upper chamber of the pot. The cylinder is then drawn by means of the drawing tool from the char e of glass in the pot in the usual manner. y the described operation the charge of glass for the draw is obtained directly from the body of glass 2 in the furnace, and the drawing opening 5 substantially closed or sealed by the pot, whereby the body of glass 2 is insulated or protected by the pot from the chilling effects of the atmosphere during the drawing action. At the same time the pot insulates the charge of glass therein from the heat of the bod of glass 2 in the furnace and exposes sai charge beyond the zone of heat in the furnace to the direct cooling effects of the atmosphere. As a result, the initial temperature of the charge of glass in the pot isno longer maintained by the heat of the furnace, but the charge is permitted to cool by direct exposure to the atmosphere. Hence the glass will more rapidly congeal about the bait and cool in the initialportion of the draw, allowing the cylinder to be drawn with much less trouble and with much greater speed than is possible in drawing the cylinder directly from the body of glass 2 or from a drawing ring or other receptacle in which the temperature of the charge of glass is influenced by the interior temperature of the furnace.

. Two substantial advantages are thus gained in the operation of drawing glass cylinders from a body of glass within a melting furnace: first, that of protecting the body of glass within the furnace from the chilling effects of the atmosphere, thus keeping the at a higher temperature and greater state of purity at the drawing station, while reducing the amount of fuel necessary to keep the body of glass at the proper temperature, and, secondly, that of isolating the charge of glass in the pot from the body of glass 2, so that the said charge will cool much more radidly-and allow the cylinder to be drawn with greater efiiciency and rapidity. A

After the cylinder is drawn and removed from the bait in the usual manner, the pot 3 may be raised to a position above the top wall a or be lowered to a position between the same and body of glass 2, as shown in dotted lines in Fig. 2, and then turned over or inverted, to bring the pot chamber which has been in use into lowermost position and to elevate the other pot chamber into position for use. The pot is then restored to the drawing position for the drawing of the succeeding cylinder. By this means, the pot chamber which has been previously used and which contains the residue or aftermath from the preceding charge is inverted and disposed above the body of glass 2, so that the residue or aftermath will be melted by the heat of the furnace and drained directly back into the furnace while the operation of drawing the glass cylinder from the glass in the upper pot chamber is being carried out.

The drain ring 34 is preferably employed and provided to receive the partially melted aftermath draining from the bottom chamber of the pot, thus segregating and confining the aftermath until it is fully melted and purified by the heat of the body of glass 2. By this means, the aftermath is prevented from passing into the main furnace and mixing with the main body of glass and from being ladled up until it is fully melted and purified. In the use of the single pot 3* instead of the double pot 3, the operation is the same as that previously described, except that the pot is inverted after each. drawing action to allow the aftermath to melt and drain back into the furnace and is then restored to an upright position for the next charging and drawing actions.

It will thus be seen that my invention provides a process whereby glass cylinders may be drawn from a pot filled directly with a charge of glass from the melting furnace, the temperature of the glass within the furnace protected during the drawing action, and the glass charge within the pot allowed to cool quickly for a rapid drawing action, thus obtaining all of the advantages, while eliminating the disadvantages, of the two methods of drawing glass cylinders hereinbefore referred to, and permitting such cylinders to be drawn with greater efficiency, rapidity and with greater economy over the methods heretofore in use.

Having thus described my invention, I claim:

1. The process of drawing glass cylinders when using as instrumentalities a glass melting furnace having a drawing station provided with a drawing opening, and a vertically movable glass receiving pot tiltable on a horizontal 'axis from a normally horizontal drawing position to an inverted draining position, and vice versa, which consists in disposing the pot within the drawing opening so as to substantially fill said opening and with its upper surface projecting slightly above the level thereof,

extracting a charge of glass from the furnace at a point laterally of and more or less remote from the drawing station, filling the chamber in the top of the pot with such charge of glass, drawing the cylinder from the charge of glass in the pot, moving the pot bodily in a vertical plane toa horizontal position out of alinement with the drawing opening and above the level of the glass in the furnace, tilting the pot on its axis to invert it and dispose the said pot chamber at the bottom of the pot and in the zone of heat of the drawing station so as to cause the aftermath to be melted thereby and to drain back into the furnace, tilting and reversing the pot to again dispose the pot chamber at the top of the pot, while said pot is above the level of the glass in the furnace, and then moving the pot bodily and vertically back, into position for the succeeding draw.

2. The process of drawing glass cylinders when using as instrmnentalities a glass melting furnace having a drawing station provided with a drawing opening, and a vertically movable glass receiving pot tiltable on a horizontal axis from a normally horizontal drawing position to an inverted draining position, and vice versa, which consists in disposing a floating drain ring upon the surface of the glass within the furnace, disposing the pot within the drawing open ing so as to substantially fill said opening and with its upper surface projecting slightly above the level thereof, extracting a charge of glass from the furnace at a point laterally of and more or less remote from the drawing station, filling the chamher in the top of the pot with such charge of glass, drawing the cylinder from the charge of glass in the pot, moving the pot bodily in a vertical plane to a horizontal position out of alinement with the drawing opening and above the level of the glass in the furnace, tilting the pot on its axis to invert it and dispose the said pot chamber at the bottom of the pot and in the zone of heat of the drawing station so as to cause the aftermath to be melted thereby and to drain hack into the furnace, tilting and reversing the pot to again dispose the pot chamber at the top of the pot, while said pot is above the Level of the glass in the furnace, then movingthe pot bodily and vertically back into position for the succeeding draw, moving the drain ring from the furnace into the drawing station pre liminary to each draining action to dispose it in position to subsequently receive the melted aftermath, and moving the ring back from the drawing station into the furnace after each draining action and preliminary to each pot charging action. a

In testimony whereof I affix my signature.

WILLIAM WVESTBURY. 

